180 OKDKU 70. COMPOSITE. 



19 C. aurea Ait. Lower Ivs. pinnately divided, upper ternately, or simple ; 1ft s?. ovate 

 to lance-linear, serrate ; rays? 6 0, obtuse ; fruit toothed. Ditches, S. 2-4f. Ang.-Oct. 



20 C. aristosa Ms. Sparingly pubescent ; Ivs. pinnately 5-9-parted, segm. lance-lin., 

 incised; hds. small, rays large; outer scales 10 12, linear; awns slender, spreading, 

 as long as the fruit. Low woods. W. 2 3f. Rays expanding 18". Aug. Oct. 

 Varies with the outer involucre leafy ; and with the awns short, &c. 



21 C. tricliosperma MX. Stem glabrous, square, dichotomous ; Ivs. pinnately 5-7- 

 parted, segm. lanceolate, cut ; rays entire, large ; cyp. narrowly cuneate, with 2 short 

 stout awns. Wet grounds, Mass, to 111. (J.Wolf), and Car. l-2f. Fls. showy. Jl.Aug. 



22 C. discoicLea T. & G. Glabrous, much branched; leaves ternate, long-pet iolate; 

 ll'ts. lance-ovate, dentate ; hds. small (2 3") ; fr. linear-cuneate, the 2 stout awns (up- 

 wardly hispid) half as long and equalling the corolla. (T) Wet, W. and S. l-3f. Jl.-Sept. 



23 C., bid.entoid.es N. Glabrous, paniculate ; Ivs. simple, lanceolate, serrate ; heads 

 7-1 y ; fr. lin.-oblong, the slender (up-hispid) awns longer than cor. Pa. Del. : rare. 



59. BIDENS, L. BURR-MARIGOLD. Invol. double. Scales somewhat 

 similar, or the outer foliaceous. Rays 4 8 (sometimes none), neutral ; 

 disk-flowers perfect. Recep. chaffy, flat. Pap. of 2 4 awns, rough back- 

 wards. Cypsela obcomprcssed, obscurely quadrangular. Leaves opposite, 

 incised. Flowers yellow. July October. (See Addenda.) 



Cypsela linear-subulate, tapering to the top, 3-4-angled, 2-6-awned Nos. 1 3 



Cypsela oblanceolate, broader at the top, flat, 2-4-awned Nos. 4 7 



1 B. leucantlia Willd. Lvs. in 35 serrate lobes : hds. with 5 white rays. S. Fla. If. 



2 B. bipiimikta L. Spanish Needles. Lvs. bipinnate, Ifrs. lanceolate, pinnatifid ; ray* 



very short, obovate, 3, 4, or ; sc. all equal in length. (5) Waste grounds, Ct. to 111. 2-4f. 



3 B. Beckii Torr. St. subsimple ; submersed Ivs. capillaceous-multifid, emersed Ivs. 



lanceolate, connate, acutely serrate or cut : rays longer than the involucre, y. Slow 

 waters. Vt. (rare), W. and N. Stem 2 3f. Heads solitary, terminal. 



4 B. froiidosa L. Beggar-ticks. Rays ; outer sc. leafy, G times longer than the fis. ; 



lower leaves pinnate, ternate, upper lanceolate, serrate ; awns 2. (T) Fields : com. 2f. 



5 B. commta Willd. Rays ; outer sc. leafy, longer than the head ; Ivs. lanceolate, 



serrate, subconnate at base, lower some trifid ; awns 3. @ Swamps, E. and W. 1 3f. 



6 B. cernua L. Rays 048, small ; hds. cernuous ; outer scales as long as the disk ; 



leaves all lanceolate, snbconnate, dentate. (T) Swamps, ditches, E. and W. 1 2f. 



7 B. chrysantliemoides L. Lvs. oblong, attenuate at each end, connate at base, 



regularly serrate ; rays thrice longer than the involucre. Ditches : common. 6'-2f. 



60. SPILANTHUS, L. Invol. shorter than the disk, double, appressed. 

 Recep. conical, chaffy, the pales embracing the flowers. Cyp. of the disk 

 compressed, with 1 3 bristly awns or awnless, of the ray (when present) 

 3-angled. Herbs with acrid taste, opposite leaves, and solitary, yellow heads. 

 Chiefly tropical. Aug. Oct. (Acmella, Rich.) 



1 S. rcpens MX. Diffuse, rooting at the lower joints ; Ivs. lanceolate, subserrate, acute 



at each end, petiolate ; rays about 12 ; fr. awnless, not ciliate. ii Wet, S. Car. to Fla. 



2 S. Nuttallii T. & G. Ascending, diffuse; Ivs. ovate to oblong, coarsely serrate ab- 



ruptly petiolate ; fruit ciliate on the margins ; rays 10-12. Bogs, E. Fla. l-2f. 



61. VERBESINA, L. CROWN-BEARD. Rays s, few or none; disk 

 . Sc. in 2 or more series, imbricated, erect. Chaff concave or embracing 

 the flowers. Achenia compressed, 2-awned. i ^> Leaves often decurrent 

 serrate or lobed. Heads solitary or corymbous. 



1 V. Siegisbecfeil MX. Stem 4-winged ; Ivs. opposite, ovate, gcrrato, acuminate, 3 



